Apparatus for heating stills.



F. T. BEERS.

APPARATUS FOR HEATING STILLS.

APPLICATION FILED mu; 3, 1914.

LMQJH 1 Patented Aug. 10,1915.

Reserra/r I ammwtoz 9 ?MW g gm FRANK TROXELL BEER-S, OF IBARKSDALE,

vWISCION'SIN', ASSIG-NOIR- TO E. I. DU PONT DE NEMOURS: POWDER COMPANY, OF WILMINGTON, DELAWARE, A CORPORATION OF NEW J APPARATUS FOR HEATING STILLS.

Specification of Letters Patent.

Patented Aug. 10, 1915.

Original application filed November 13, 1913, Serial N 0. 801,175. Divided and this application filed June 3, 1914. Serial No. 842,694.

To all whom it may concern Be it known that I, FRANK TROXELL BEERS, of Barksdale, in the county of Bayfield, and in the State of Wisconsin, have in-' vented a certain new and useful Improvement in Apparatus for Heating Stills, and do hereby declare that the following is a full, clear, and exact description thereof.

My invention relates to an apparatus for heating retorts, but it is applicable especially for the heating of retorts used for the distillation of nitric acid. It is, however, also applicable .to the heating and evaporation of aqueous and other solutions.

My invention is particularly applicable to the heating of retorts containing sodium nitrate and sulfuric acid in the process of making nitric acid.

Hitherto it has been customary to distil' nitric acid from sodium nitrate and sulfuric acid by heating the same in cast iron retorts set in brickwork and fired directly from a coal or oil fire. These retorts have, however, been increasing in size until they have reached, in some instances, a capacity of 20,000 pounds, and as a result considerable difliculty has been experienced from the cracking of the retorts due to uneven heating. None of the plans previously. proposed to avoid this uneven heating and to avoid the strain produced in the comparatively thick walls of the retorts have been sat1sfactory.

- The objectof my invention is to heatsuch retorts and their contents in an even manner so as to avoid. the disadvantages above referred to. My invention comprises in general an 11111 provement in heating, retorts and thelr contents in which a retort of any desired shape; such as a spherical, cylindrical/or other shape, is provided with meansfor heating the retort indirectly, as for example, bythe use of a jacket provided with a circulating current of a high-boiling liquid, as for example, oil,

By means of my inventlon a better regulation of the temperature used in the distlllation can be obtained which results in a better yield of nitric acid'because of the smaller amount of loss due to fumes produced by sudden changes in pressures. Furthermore, a purer and stronger acid is obtained because local overheating and consefuel used owing to the fact that my-process is a more efficient method for heating retorts, and as there is much less labor required in order to operate my process. Furthermore,-my process is more sanitary inasmuch as when the retorts crack poisonous fumes escape.

While my invention is capable of embodiment in many different forms, for the purpose of illustration, I have shown one type of apparatus which may be used in carrying out my invention, in which the figure is a dlagrammatic representation of an elevation of an apparatus made in accordancewith my lnvention.

In the drawings, 1 have shown a retort 1, of any suitable material, as for example cast iron, having an exit pipe 2. Theretort l-is surrounded with a jacket 3. An inlet pipe 4 connects with the upper portion of said Jacket, said pipe having a valve 5. The

pipe 4 communicates with a supply pipe 6 leading from a pump 7 of any desired construction. From the pump 7 a pipe 8100mmunicates with an outlet pipe 9, having a valve 10, leading from an oil heater 11, constructed and heated in any suitable manner. Oil from the circulating system is fed into the heater 11 from a pipe 12, which communicates with a pipe 13, having a valve 14:. The pipe 12 also communicates with an expansion reservoir 15 by means of a pipe 16,

the expansion reservoir 15 being open to the outer air. It will be noted that the expansion reservoir 15 is located above the highest point of the circulating system, so as to prevent the overflowof oil. As indicated in the drawings a pipe 13 communicates with the lower portion of the jacket 3 and communicates by means of a by-pass pipe 16, having a valve 17, with the point of union of the pipes 4: and 6. Another pipe 18, having a valve 18, leads from the pipe 13 to a cold oil tank 19. This cold oil tank 19 has an outlet pipe 20 provided with a valve 21 to permit the oil to be drawn oif when desired, and from the pipe 20 there is a pipe 22, which has a valve 23, and communicates with the two pipes 8 and 9 where 55 quent decomposition are avoided. Again, the same are joined together. The parts conveying heated oil are preferably covered with lagging 24.

In the operation of my invention, when the same is carried out in connection with the apparatus previously described, it will be assumed that the current of oil such as mineral oil, as for example, an oil of high flash point, is to be put in circulation for the pur ose of heating the retort 1. The valves 1 and 23 will then be closed while the remaining valves, except valve 21, will be in open position. When the pump 7 is thrown into operation a current of oil drawn from the heater 11 will be forced through pipes 9, 8, 6 and 4: into the jacket 3 from which the current of oil will be forced through the pipes 13 and 12 back into the heater 11. By this means a circulating current of oil is produced which heats the retort evenly throughout. The temperature of the retort may be readily varied by controlling the temperature of the oil in the jacket 3 through the operation of valves 17 and 5, owing to the variation in the quantity of the heated oil supplied to the jacket. If at any time the retort becomes overheated for disconnected from the system and a body of cold oil may be circulated through the jacket 3 by closing the valves 17, 10 and 14:, and opening the remaining valves, except valve 21. When the retort has again reached the desired temperature the valves can again be operated so as to circulate a current of heated oil through the jacket 3 in the manner already described. If at any time it is desired to draw 016? the oil from the tank 19 and from the circulating system including the jacket 3, the valve 21 may be opened for this purpose.

This application is adivision of my applicatlion, Serial No. 801,175, filed November 13, 19 3.

While I have described my invention above in detail, I wish it to be understood that many changes may be made therein without departing from the spirit of my invention; for instance, instead of heating or cooling the retort by means of liquid in the outer jacket such liquid may be contained within coils located inside the retort, or outside the retort and inside the jacket,

or both the jacket and such coils may be used. I

I claim:

1. In combination, a still for distilling nitric acid having a container for a heating or cooling medium, said container being out of communication with the portion of said still adapted to receive the charge, and means for controlling the temperature of the still, comprlsing a by-pass for the heating medium around the still.

2. In combination, a still for distilling nitric acid having a container for a heating medium, said container being out of communication With the portion of said still supplying a cooling medium to the still.

4. In combination, a still for distilling nitric acid having a jacket, means for circulating a heating medium through the same,

and means for controlling the temperature of the still, comprising a by-pass for the medium around the still.

5. In combination, a still for distilling nit ic acid having a jacket, means for circulating a heating medium through the same, comprising a pump and a heating means, and means for controlling the temperature of the still, comprising a by-pass for the medium around the still.

6. In combination, a still for distilling nitric acid having a acket, means for circulating a heating medium through the same,

and means for controlling the temperature of the still comprising a means for supplying a cooling medium to the still.

In combination, a still for distilling nitric acid having a jacket, means for circulating a heating medium through the same,

comprising a pump and a heating means, and means for controlling the temperature of the still comprising a means for supplying a cooling medium to the still.

In combination, a still for distilling nitric acid having a jacket, means for circulating a heating medium'through the same,

and means for relieving pressure in the circulating means, comprising an expansion reservoir.

9. In combination, a still for distilling nitric acid having a jacket, means for circulatin'ga heating medium through the same,

comprising a pump and a heating means,

and means for relieving pressure in the circulating means, comprising an expansion reservoir.

In testimony that I claim the foregoing I have hereunto set my hand.

FRANK TROXELL BEERS. Witnesses:

P. E. S'rRIC-KLAND, R. W. KIEssLING. 

